Journal of Cell Science 115, e1105-e1105 (2002)
© 2002 The Company of Biologists Limited
Microtubule nucleation in plants
Microtubule nucleation in yeast and animal cells is initiated by
-tubulin ring complexes (-TuRCs) associated with centrosomes or
spindle pole bodies. Microtubule nucleation in plants is less well understood:
the microtubule arrays differ significantly from those in animals and lack
centrosome-like microtubule-organizing centres (MTOCs). Moreover,
-tubulin is distributed along plant microtubules rather than at one
end, which is perplexing given its role in nucleation in animals and yeast.
Anne-Catherine Schmit and co-workers now provide evidence that plants do in
fact use -TuRC-like structures to nucleate microtubules (see
p. 2423). They have cloned and
characterized rice and Arabidopsis orthologues of the -TuRC
component SPC98, demonstrating that higher plants contain -TuRC
components other than -tubulin. Significantly, SPC98 does not
colocalize with -tubulin along the length of plant microtubules but
does colocalize with it at the nuclear surface and cell cortex - locations for
putative plant MTOCs. These findings suggest that -TuRCs containing
SPC98 and -tubulin function in microtubule nucleation at plant MTOCs
but that -tubulin decorating the length of microtubules has an
additional, -TuRC-independent function.
Related articles in JCS:
- The plant Spc98p homologue colocalizes with -tubulin at microtubule nucleation sites and is required for microtubule nucleation
- Mathieu Erhardt, Virginie Stoppin-Mellet, Sarah Campagne, Jean Canaday, Jérôme Mutterer, Tanja Fabian, Margret Sauter, Thierry Muller, Christine Peter, Anne-Marie Lambert, and Anne-Catherine Schmit
JCS 2002 115: 2423-2431.
[Abstract]
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